Here’s where we get to the meat of the matter. While it may sound complicated at first, the tables will give you some clear data about what vegetables will work together. Sequential cropping is one of the key variables in intensive planting.
Two Distinct Problems With Temperature
The reality is that we face two distinct kinds of problems with our vegetables when it comes to temperature preferences.
And sorting out these temperature preferences is the key to sequential planting.
The first is that some crops have specific temperatures they require to grow properly.
For example, peas and spinach will only grow well in cool soils and cool temperatures. These crops simply don’t grow well in hot temperatures. You’ll want to plant these in the spring and fall to avoid the heat of the summer. Some plants such as potatoes will grow in both cool and warm so you can plant early or late, harvesting early or late depending on the variety and how large you want the tuber to be.
Other plants such as tomatoes and peppers will only grow in warm temperatures so you’ll have to plant them once the ground has warmed up.
The second of these temperature related problems is where you’re gardening and how long your growing season is.
If you live in a zone 3, then your short season is going to mean that a plant such as a tomato is going to occupy one growing area for the entire growing season and your interplanting will be growing shade-tolerant plants around its base. You simply don’t have the time to ripen a crop of radish or spinach before those tomatoes have to go into the ground.
However, if you live in a zone 7, you’ll very well be able to take a spinach or pea crop out of the ground before the tomatoes are planted. I can just do this in my zone 4/5 garden.
Cool Loving Plants
All of these dates are approximate but are set for a zone 4.
For every zone warmer, you can adjust by roughly a week.
All sowing and pack growing is done indoors, transplanting refers to outdoor transplanting. If the “transplant” section is empty it simply means the sowing is done directly outdoors and not transplanted.
Crop Sow/ Transplant Harvest
Beets – crop 1 mid-March mid-April early-May
Beets – crop 2 mid-April outdoors early May thin late June
Broccoli early March mid-April mid-June
Brussels Sprouts early March mid-April mid-June, early July
Cabbage early March mid-April mid-late July
Carrot early March mid-April late May
Carrot – crop 2 mid-April outdoors thin as appropriate late June
Cauliflower mid March mid April early July
Celery early March early May early July
Endive early March late April mid to late June
Kale early March early April early May
Kale crop 2 early April early May late May
Leek early March mid April late July
Lettuce late March late April late May
Onion early March early April late June
Onion crop 2 early April early May mid July
Parsley late Feb mid April end May
Parsnip early March mid April mid July
Pea mid-March outdoors late May
Pea crop 2 late April outdoors late June
Potato mid-April outdoors early July
Radish early April outdoors early May
Radish crop 2 early May outdoors early June
Rutabaga early March early April late May
Spinach late March late April mid May
Swiss Chard late March late April late May
Mid Season Plants
These are the plants that thrive on summer’s heat and do not grow well in cool soils or cool air temperatures. These are planted after the cool temperature crops have had their day in the sun.
Crop Sow/Transplant Harvest
Bean mid April end May mid July
Carrot end May early Aug
Corn mid May mid June mid to end Aug
Cucumber mid May mid June end July
Eggplant mid April end May mid Aug
Melon mid April end May end July
Pepper mid April end May mid Aug
Potato end May mid Sept
Pumpkin early June mid Oct
(continual growing) mid April
end June end May
mid Aug end June
Squash, winter mid April end May end Aug
Squash, winter end May mid-Sept
Sweet Potato mid April end May, early June early Sept
Tomato end March end May mid Aug
Watermelon end Aprilå end May mid Aug
late Season Plants
Then we have the plants that grow well in the shortening days, cool air temperatures but warm soil of the late summer and early fall.
Crop Sow /Transplant Harvest
Beet mid Aug mid Sept end Sept- early Oct
Broccoli end June early Aug late Sept
Brussels Sprouts mid June end July October
Cabbage mid June end July October
Carrot mid July late Sept
Cauliflower mid July end July October
Celery early July mid Sept October
Chicory mid July mid Aug October
Kale end July mid Sept October
Kohlrabi mid Aug mid Sept October
Lettuce end Aug end Sept October
Onion end June begin Aug October
Parsnip end June October
Pea mid July October
Radish mid August on weekly end September on
Spinach end Aug mid Sept October
Swiss Chard mid Aug mid Sept October
Turnip early Aug early Sept October
Putting All That Information Together
Let me summarize the preceding information.
We want to ensure there’s not a single square foot of garden space left unplanted so we’re going to match our plants for height, next to plants with complementary leaf coverage, in a sequence of planting and transplanting from early April right through to harvesting in October.
As one plant is harvested, another transplant is ready to go directly into its space.
The theory versus the reality
The theory is really nice in all of these intensive planting schemes but the hard cold reality is that it takes a lot of work and a lot of planning (not to mention constant attention to the small details) for this kind of gardening to really be successful. You may decide to implement a few of these things in your first attempt using only the plants you really like to eat. Multiple crops of salad “stuff” like lettuce and spinach are the easiest first step. After you master those, go onwards from there.
Another useful point to keep in mind is the timing of each of these crops will vary from garden area to area. The times here are scheduled for a zone 4 and if you live in a warmer or colder area, you’ll be able to adjust your timing accordingly. And just to really make you frustrated (join the gardening club here) is that every season is different – we’ll have a cold wet spring one year and a short hot one the next. All of these planning steps have to be flexible and there is no one size fits all every season.
Having said all that, it is fairly easy to begin if you take the following steps.
Steps for Success
Pick the vegetables for cool season that you want to grow. Decide how many times during the season you can grow them. (early, mid and late season crop tables) Do not bother growing plants you’ll never eat or that you eat infrequently.
Decide how best to combine them in the garden. Which plants go next to which plants. (above ground growing pattern section)
Decide which plants can tolerate some shade and put them in combination if you can. (light and shade tolerant section) Try to put the shade tolerant plants under or next to the sun-demanding plants.
The best beginner advice I can give you is to always combine a long and a short term crop on the same bed if you possibly can. That way, you’ll be growing the long season crop and harvesting the short season crop. The ground will do double-duty.